Guide: How to turn your Custom GPT into a Skill

OpenAI is shutting down Custom GPTs on December 11, 2026, and replacing them with plugins, where the instructions live in a so-called Skill: a fixed workflow with instructions, examples and possibly code, which ChatGPT can use on its own when it fits the task. Here's what you need to do.

Before you move

1. Make a list of the GPTs you use, and check who created them. Only the creator can move a GPT, and in business accounts also an administrator. If you use other people's GPTs, you have to wait for the creator to make a replacement.

2. Finish the last edits and publish the GPT. The migration takes the most recently published version, so drafts are not included. You don't need to share it publicly.

3. Save three or four tasks you usually give the GPT, plus one difficult example. You will need them to compare the answers afterward.

How to move it

4. Go to My GPTs and choose "Migrate to plugin" next to the GPT you want to move. If you don't see the button, the migration is not yet open for your account, or plugins are turned off.

5. Review the instructions and files in the new plugin.

6. Test with the saved tasks: Does ChatGPT pick the right Skill, does it use the right files, and does the answer come in the format you need? If your GPT pulls data from other systems through so-called custom actions, that connection has to be rebuilt, because it does not move over.

7. Share the plugin with those who used the old GPT. It starts out as private, and they do not get access on their own.

Afterward, you bring up the plugin by typing @ and the name, or by choosing + and More. ChatGPT can also use an installed Skill on its own when the description matches what you are asking for.

Create your first Skill from scratch

If you have no GPTs to move, start with a task you do over and over, such as quotes, meeting prep or the monthly report. Go to Plugins in the sidebar, choose the Skills tab, and click Create and then Create with chat. You can also simply ask ChatGPT to create a Skill in a regular conversation. ChatGPT then uses its built-in skill-creator and asks follow-up questions.

Describe the task as you would explain it to a new colleague: What triggers it, what information is needed, which steps should be followed, and when should a human approve the result? According to OpenAI, Skills are available for Business, Enterprise, Healthcare and Edu accounts.

It can pay off especially in smaller companies. OpenAI's own study of more than 800,000 work-related messages from US ChatGPT users showed in July that 43.5 percent of the field-specific messages were about tasks from a field other than the user's own, such as a salesperson analyzing data or an owner reviewing a contract themselves. Among users with an average activity level, the share was 18.9 percent in workspaces with 2-5 users versus 16.3 percent in those with more than 100. A Skill can ensure that such tasks are handled the same way every time.